INTRO(3LIBIIO)

NAME

libiio-0.25 - introduction to libiio, a library for interacting with the Linux IIO subsystem and devices

SYNOPSIS

#include <iio.h>

cc file.c -liio

OPTIONS

The define IIO_CHECK_REG will warn if return values are not checked. Most libiio functions, if/when a failure occurs will return a negative error number. this warning will ensure these error numbers are looked at. There is nothing more frustraining than calling a function, debugging some hardware, and then eventually realizing there was a typo in an attribute name. This option will force libraries users to at least capture the return value.

cc file.c -DIIO_CHECK_REG -liio

DESCRIPTION

libiio is a library used to interface to the Linux Industrial Input/Output (IIO) Subsystem. The Linux IIO subsystem is intended to provide support for devices that in some sense are analog to digital or digital to analog converters (ADCs, DACs). This includes, but is not limited to ADCs, Accelerometers, Gyros, IMUs, Capacitance to Digital Converters (CDCs), Pressure Sensors, Color, Light and Proximity Sensors, Temperature Sensors, Magnetometers, DACs, DDS (Direct Digital Synthesis), PLLs (Phase Locked Loops), Variable/Programmable Gain Amplifiers (VGA, PGA), and RF transceivers. You can use libiio natively on an embedded Linux target (local mode), or use libiio to communicate remotely to that same target from a host Linux, Windows or MAC over USB, Ethernet or Serial.

DATA TYPES

The library makes use of C structures and typedefs to promote portability, and is known to run on various GNU/Linux distributions, macOS, Windows, and mbed (via tiny-iiod). The main C structures are:

iio_scan_context: The scanning context
iio_context_info: The information related to a discovered context
iio_context: Contains the representation of an IIO context
iio_device: Represents a device in the IIO context
iio_channel: Represents an input or output channel of a device
iio_buffer: An input or output buffer, used to read or write samples
iio_data_format: Contains the format of a data sample.

LIST OF ROUTINES

The following routines are part of the library. Consult the Doxygen pages for details on their operation (in the SEE ALSO section).

Scan Functions for scanning available contexts

Function: Description
iio_create_scan_context: Create a scan context
iio_scan_context_destroy: Destroy the given scan context
iio_scan_context_get_info_list: Enumerate available contexts
iio_context_info_list_free: Free a context info list
iio_context_info_get_description: Get a description of a discovered context
iio_context_info_get_uri: Get the URI of a discovered context
iio_create_scan_block: Create a scan block
iio_scan_block_destroy: Destroy the given scan block
iio_scan_block_scan: Enumerate available contexts via scan block
iio_scan_block_get_info: Get the iio_context_info for a particular context

TopLevel Top-level functions

Function: Description
iio_library_get_version: Get the version of the libiio library
iio_strerror: Get a string description of an error code
iio_has_backend: Check if the specified backend is available
iio_get_backends_count: Get the number of available backends
iio_get_backend: Retrieve the name of a given backend

Context Context

Function: Description
iio_create_default_context: Create a context from local or remote IIO devices
iio_create_local_context: Create a context from local IIO devices (Linux only)
iio_create_xml_context: Create a context from XML data in memory
iio_create_xml_context_mem: Create a context from XML data in memory
iio_create_network_context: Create a context from the network
iio_create_context_from_uri
iio_context_clone: Duplicate a pre-existing IIO context
iio_context_destroy: Destroy the given context
iio_context_get_version: Get the version of the backend in use
iio_context_get_xml: Obtain a XML representation of the given context
iio_context_get_name: Get the name of the given context
iio_context_get_description: Get a description of the given context
iio_context_get_attrs_count: Get the number of context-specific attributes
iio_context_get_attr: Retrieve the value of a context-specific attribute
iio_context_get_attr_value: Retrieve the value of a context-specific attribute
iio_context_get_devices_count: Enumerate the devices found in the given context
iio_context_get_device: Get the device present at the given index
iio_context_find_device: Try to find a device structure by its ID, label or name
iio_context_set_timeout: Set a timeout for I/O operations

Device Device

Function: Description
iio_device_get_context: Retrieve a pointer to the iio_context structure
iio_device_get_id: Get whether or not the device is a hardware monitoring device
iio_device_get_name: Retrieve the device name
iio_device_get_label: Retrieve the device label
iio_device_get_channels_count: Enumerate the channels of the given device
iio_device_get_attrs_count: Enumerate the device-specific attributes of the given device
iio_device_get_buffer_attrs_count: Enumerate the buffer-specific attributes of the given device
iio_device_get_channel: Get the channel present at the given index
iio_device_get_attr: Get the device-specific attribute present at the given index
iio_device_get_buffer_attr: Get the buffer-specific attribute present at the given index
iio_device_find_channel: Try to find a channel structure by its name of ID
iio_device_find_attr: Try to find a device-specific attribute by its name
iio_device_find_buffer_attr: Try to find a buffer-specific attribute by its name
iio_device_attr_read: Read the content of the given device-specific attribute
iio_device_attr_read_all: Read the content of all device-specific attributes
iio_device_attr_read_bool: Read the content of the given device-specific attribute
iio_device_attr_read_longlong: Read the content of the given device-specific attribute
iio_device_attr_read_double: Read the content of the given device-specific attribute
iio_device_attr_write: Set the value of the given device-specific attribute
iio_device_attr_write_raw: Set the value of the given device-specific attribute
iio_device_attr_write_all: Set the values of all device-specific attributes
iio_device_attr_write_bool: Set the value of the given device-specific attribute
iio_device_attr_write_longlong: Set the value of the given device-specific attribute
iio_device_attr_write_double: Set the value of the given device-specific attribute
iio_device_buffer_attr_read: Read the content of the given buffer-specific attribute
iio_device_buffer_attr_read_all: Read the content of all buffer-specific attributes
iio_device_buffer_attr_read_bool: Read the content of the given buffer-specific attribute
iio_device_buffer_attr_read_longlong: Read the content of the given buffer-specific attribute
iio_device_buffer_attr_read_double: Read the content of the given buffer-specific attribute
iio_device_buffer_attr_write: Set the value of the given buffer-specific attribute
iio_device_buffer_attr_write_raw: Set the value of the given buffer-specific attribute
iio_device_buffer_attr_write_all: Set the values of all buffer-specific attributes
iio_device_buffer_attr_write_bool: Set the value of the given buffer-specific attribute
iio_device_buffer_attr_write_longlong: Set the value of the given buffer-specific attribute
iio_device_buffer_attr_write_double: Set the value of the given buffer-specific attribute
iio_device_set_data: Associate a pointer to an iio_device structure
iio_device_get_data: Retrieve a previously associated pointer of an iio_device structure
iio_device_get_trigger: Retrieve the trigger of a given device
iio_device_set_trigger: Associate a trigger to a given device
iio_device_is_trigger: Return True if the given device is a trigger
iio_device_set_kernel_buffers_count: Configure the number of kernel buffers for a device

Channel Channel

Function: Description
iio_channel_get_device: Retrieve a pointer to the iio_device structure
iio_channel_get_id: Retrieve the channel ID
iio_channel_get_name: Retrieve the channel name
iio_channel_is_output: Return True if the given channel is an output channel
iio_channel_is_scan_element: Return True if the given channel is a scan element
iio_channel_get_attrs_count: Enumerate the channel-specific attributes of the given channel
iio_channel_get_attr: Get the channel-specific attribute present at the given index
iio_channel_find_attr: Try to find a channel-specific attribute by its name
iio_channel_attr_get_filename: Retrieve the filename of an attribute
iio_channel_attr_read: Read the content of the given channel-specific attribute
iio_channel_attr_read_all: Read the content of all channel-specific attributes
iio_channel_attr_read_bool: Read the content of the given channel-specific attribute
iio_channel_attr_read_longlong: Read the content of the given channel-specific attribute
iio_channel_attr_read_double: Read the content of the given channel-specific attribute
iio_channel_attr_write: Set the value of the given channel-specific attribute
iio_channel_attr_write_raw: Set the value of the given channel-specific attribute
iio_channel_attr_write_all: Set the values of all channel-specific attributes
iio_channel_attr_write_bool: Set the value of the given channel-specific attribute
iio_channel_attr_write_longlong: Set the value of the given channel-specific attribute
iio_channel_attr_write_double: Set the value of the given channel-specific attribute
iio_channel_enable: Enable the given channel
iio_channel_disable: Disable the given channel
iio_channel_is_enabled: Returns True if the channel is enabled
iio_channel_read_raw: Demultiplex the samples of a given channel
iio_channel_read: Demultiplex and convert the samples of a given channel
iio_channel_write_raw: Multiplex the samples of a given channel
iio_channel_write: Convert and multiplex the samples of a given channel
iio_channel_set_data: Associate a pointer to an iio_channel structure
iio_channel_get_data: Get a pointer to a channel's data format structure
iio_channel_get_type: Get the type of the given hwmon channel
iio_channel_get_modifier: Get the modifier type of the given channel

Buffer Buffer

Function: Description
iio_buffer_get_device: Retrieve a pointer to the iio_device structure
iio_device_create_buffer: Create an input or output buffer associated to the given device
iio_buffer_destroy: Destroy the given buffer
iio_buffer_get_poll_fd: Get a pollable file descriptor
iio_buffer_set_blocking_mode: Make iio_buffer_refill() and iio_buffer_push() blocking or not
iio_buffer_refill: Cancel all buffer operations
iio_buffer_push: Cancel all buffer operations
iio_buffer_push_partial: Send a given number of samples to the hardware
iio_buffer_cancel: Cancel all buffer operations
iio_buffer_start: Get the start address of the buffer
iio_buffer_first: Find the first sample of a channel in a buffer
iio_buffer_step: Get the step size between two samples of one channel
iio_buffer_end: Get the address that follows the last sample in a buffer
iio_buffer_foreach_sample: Call the supplied callback for each sample found in a buffer
iio_buffer_set_data: Associate a pointer to an iio_buffer structure
iio_buffer_get_data: Retrieve a previously associated pointer of an iio_buffer structure
iio_device_get_sample_size: Get the current sample size
iio_channel_get_index: Get the index of the given channel
iio_channel_get_data_format: Get a pointer to a channel's data format structure
iio_channel_convert: Convert the sample from host format to hardware format
iio_channel_convert_inverse: Convert the sample from host format to hardware format
iio_device_get_debug_attrs_count: Enumerate the debug attributes of the given device
iio_device_get_debug_attr: Get the debug attribute present at the given index
iio_device_find_debug_attr: Try to find a debug attribute by its name
iio_device_debug_attr_read: Read the content of the given debug attribute
iio_device_debug_attr_read_all: Read the content of all debug attributes
iio_device_debug_attr_write: Set the value of the given debug attribute
iio_device_debug_attr_write_raw: Set the value of the given debug attribute
iio_device_debug_attr_write_all: Set the values of all debug attributes
iio_device_debug_attr_read_bool: Read the content of the given debug attribute
iio_device_debug_attr_read_longlong: Read the content of the given debug attribute
iio_device_debug_attr_read_double: Read the content of the given debug attribute
iio_device_debug_attr_write_bool: Set the value of the given debug attribute
iio_device_debug_attr_write_longlong: Set the value of the given debug attribute
iio_device_debug_attr_write_double: Set the value of the given debug attribute
iio_device_identify_filename: Identify the channel or debug attribute corresponding to a filename
iio_device_reg_write: Set the value of a hardware register
iio_device_reg_read: Get the value of a hardware register

Hwmon Compatibility with hardware monitoring (hwmon) devices

24 September 2023

libiio-0.25